In a process of implementing the technical solutions of the embodiment of the disclosure, the inventor of the disclosure found that a conventional art at least has the following technical problems.
In a wireless communication technology, a Wireless Local Area Network (WLAN) consistent with standard Institute of Electrical and Electronic Engineers (IEEE) 802.11 has been used most widely, and it is not only used for laptop computers, handheld apparatus and mobile terminals in various special environments, but also is considered to be used in a technology of hotspot access with the Internet in a 3rd Generation Partnership Project (3GPP) system of a cellular network. The IEEE 802.11 working group defines a series of WLAN technical standards such as 802.11a, 802.11b and 802.11g, and then other task group devoted to developing specifications involving technical improvements of existing 802.11 appear one after another. For example, the 802.11n task group expresses a requirement on High Throughput (HT) to support a data rate of 600 Mbps. The 802.11ac task group proposes the concept of Very High Throughput (VHT) to increase the data rate to 1 Gbps. Other 802.11-series protocols further include 802.11ad supporting work in 60 GHz and 802.11ah supporting work below 1 GHz.
In 802.11, an Access Point (AP) and multiple non-AP Stations (STAs) associated with the AP form a Basic Service Set (BSS). At present, 802.11 supports two method, virtual carrier detection and physical carrier detection, for determining whether a channel is clear, and only when a channel is determined to be clear by both virtual carrier detection and physical carrier detection, STAs may compete for sending. Virtual carrier detection refers to that a third-party STA except both parties involved in communication sets a value of a local Network Allocation Vector (NAV) according to a duration field in a radio frame when receiving the radio frame of which a receiving address is not the third-party STA, and when the NAV is not zero, determines that a channel is busy and does not compete for sending. Physical carrier detection refers to channel detection technology of Clear Channel Assessment (CCA), and an associated STA detects strength of a signal of a medium to judge whether a channel is busy or clear. Specifically, an associated STA sets different detection thresholds for different channel bandwidths, and for example, a signal detection threshold for a 20 MHz channel set by the associated STA is −82 dBm, and a signal detection threshold for a 40 MHz channel set by the associated STA is −79 dBm. On a 20 MHz channel, if a received signal is an 802.11 signal and its strength is higher than −82 dBm, it is determined that the channel is busy and a physical layer of an associated STA sends an indicator about a busy state of the channel to a Media Access Control (MAC) layer. When the received signal is an 802.11 signal and its strength is lower than −82 dBm, it is determined that the channel is clear and the physical layer of the associated STA may send an indicator about a clear state of the channel to the MAC layer.
Existing CCA has problems as follows. As shown in FIG. 1, STA1 is associated with AP1, STA2 is associated with AP2, and FIG. 1 shows strength of a signal received from each other. When STA1 sends a signal to AP1, if STA2 receives the signal of STA1 and strength of the signal is higher than a detection threshold −82 dBm, STA2 determines that a channel is busy, so that STA2 will not send any signal to AP2. Actually, if STA2 sends a signal to AP2, there may not be any interference to reception of AP1 and AP2 can successfully receive the signal of STA2, because strength of the signal of STA2 arriving at AP1 is far lower than the strength of the signal of STA1 arriving at AP1. As can be seen, an excessively high CCA detection threshold results in a detection result that the channel is busy for STA2 and reduces a sending chance of STA2.
From the above, adoption of a fixed-threshold-based CCA technology for channel detection may cause problems. Although a dynamic channel detection threshold mechanism proposed at present may increase sending chances by adopting variable detection thresholds for performing the channel detection, keeping adopting the variable detection thresholds may also cause some problems. That is, adopting fixed detection thresholds and keeping adopting dynamic channel detection thresholds both have problems. In a related technology, for the problem of how to use a detection threshold for performing the channel detection, there is yet no effective solution.